1. Field of the Invention
The present invention relates to a zipper applicator used in combination with a horizontal form, fill, seal and separate packaging machine. The applicator of this invention is uniquely characterized by its construction for placing the zipper into the fold of the web used to make reclosable containers to ensure accurate and secure attachment of the zipper to the web. The applicator is further characterized by its construction to provide vertical adjustability, so that bags of different sizes (height/depth) may be formed.
2. Description of the Prior Art
It is well known in the packaging industry and in the prior art to form, fill, seal and separate containers on machines generally known as either horizontal or vertical packaging machines. In recent years, it has also become quite commonplace for both vertical and horizontal machines to include structure whereby reclosable fasteners, referred to as “zippers” in the disclosure of this application, may be attached to the containers so that the containers are reclosable by the end user.
As the desirability of such reclosable packages to end users has been recognized, the packaging industry has developed numerous means for applying zippers to flexible film packages so as to provide reclosable containers. However, numerous obstacles have been encountered with regard to accurate and efficient means for placing the zipper on the package both accurately and securely. This is, of course, extremely important with regard to the packaging of food and medical items where security and reliable operability of the reclosable fastener are extremely important.
Inasmuch as the applicator of the present invention is particularly suited for use in combination with horizontal form, fill, seal and separate packaging machines, attention is invited to U.S. Pat. No. 5,036,643 as an example of one such prior art device. However, unlike the applicator of the present invention, that patent discloses and teaches attaching one half of the zipper closure to the flexible web before it is folded upon itself for making the container, and then attaching the other side of the zipper to the folded web.
An even earlier prior art device is disclosed in U.S. Pat. No. 4,945,714, and teaches that the zipper fastener halves are already attached to the web before entering the packaging machine. Obviously, then, careful registry must be maintained so that the two halves of the zipper mate properly when the web is folded upon itself to begin making the reclosable containers.
It is therefore clear that there remains a great need in the art for a zipper applicator usable in combination with a horizontal form, fill, seal and separate packaging machine so that the zipper will be placed accurately within the container for proper, substantially hermetic sealing to the bag web material. Furthermore, such an applicator should be capable of relatively simple adjustment to accommodate the manufacturer of reclosable containers of various sizes.